This simple two-tube broadcast receiver appeared sixty years ago this month in the October 1956 issue of the British Radio Constructor magazine.

One tube serves as the regenerative detector, with the other tube serving as AF amplifier to drive the speaker.  The set uses what is called a “metal rectifier,” although a modern semiconductor diode would probably be much more reliable.

The set runs directly off the AC mains, and the article notes a number of safety precautions, and the article assures that “if the precautions mentioned are taken, and the receiver fitted in a wooden cabinet, it will be quite safe.”  In particular, in addition to being completely surrounded the an insulating cabinet, the article notes that all metal components must be insulated.  The knob on the tuning capacitor must be covered with a non-conductive knob (with the hole for the setscrew filled in with insulating material), the switch must not come in contact with the chassis. and the bolts holding the chassis to the panel must be covered.  The plans give instructions for wiring the set for either 110 or 250 volts.

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